GTA
Airguns by Make and Model => Vintage Air Gun Gate => Topic started by: RBQChicken on April 20, 2023, 11:31:43 AM
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I’m resealing my ‘68 Blue Streak and have a couple of questions about replacement parts I’ve ordered.
The inlet check valve that Mac1 sells these days has one flat side, and the other side is concave, but rises to a point in the center (Mac1 photo below). I assume the concave side goes in facing down (front side of the valve). Is this correct? If so, is it still necessary to seat it first by giving it a whack once it’s in place?
My second question isn’t actually a question, just an observation. I bought a replacement exhaust valve from Crosman, and when I ordered it (replacement part# 397-038) I was told it was replaced by #397-038C. There’s a pic of it below, next to an original Sheridan exhaust valve. It will work just fine, but obviously will use up more valve volume. Maybe that will result in higher pressure buildup?
Anyone know what the nail-like part is for on newer guns?
Thanks.
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I don't know about the Mac-1 intake as I use the factory brass button style, but that exhaust valve with the pierce pin would be originally for CO2 guns a la Benji G39x, Sheridan E & F.
Don R.
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Mac 1 check valves usually have a "X" marked on the side that you see facing you when looking down the tube after dropping it in. It is the side you strike with a dowel to set the seal to the seat. That was the way mine was marked and the web site still shows that in the instructions. As oldair said that is a piercing pin valve for CO2 cartridges.
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The current check valves don't have the "X". They are flat on one side and have the bump in the middle as shown in the picture above. I thought it was a little concave around the bump but it may not be. The bump in the middle is actually higher than the rest of the valve.
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The current check valves don't have the "X". They are flat on one side and have the bump in the middle as shown in the picture above. I thought it was a little concave around the bump but it may not be. The bump in the middle is actually higher than the rest of the valve.
I haven't used one of Tims check valves, but if I had to hazzard a guess, I would say the flat side is the valve, and the concave side a spring alignment?
John at northwest airgun,s youtube channel installs one of those, but I think I would just call Tim. 1-562-961-6221.
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Thanks everyone. Interesting to know about that exhaust valve. I suppose Crosman decided to just go with one valve style rather than two since it will work in both gas and pump up guns.
I checked out Northwest Airguns Youtube on this and he shows the side with the nub going down first. The other side (the flat side) didn't have any x or other marking, that's why I was unsure. I had already installed it correctly (nub side down) and whacked it, but was getting a little bit of a leak so I tore it apart again and will re-whack it once I polish that seat a little better.
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Not sure why you posted the to exhaust valves. The top one for air guns, the bottom one is for CO2. The reason Crosman change the 397-038 to 397-038C is because the C stand for China. They all so went up $1.55 more.
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I ordered the 397-038 and they sent me this CO2 valve. I remembered when I gave the Crosman parts guy the 397-038 number he said something like " that's been replaced with ....." and then they sent me this CO2 valve which was labeled 397-038C.
I showed an old Sheridan valve (which has bad seals) and the new valve Crosman sent me. Either they sent me the wrong valve, or they decided to only offer the CO2 valve going forward because it works in either type of gun and easier to just make and sell one.
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The nipple side goes toward the valve seat, give it one firm rap with a mallet and wood dowel to seat it.
Have Fun!
Cheers,
Rich
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Wow, I can't believe I haven't checked in on this site in awhile. I usually check in at least a couple times a day. Thanks for the advice Rich. That's what I did, and at first it didn't work but I tore it apart again and polished the seat (the first time I was a little lazy and looked at the seat with my bore sight and figured "good enough" - it wasn't). That did the job and she holds real well now.
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Glad you got her going!